Preparation and optimization of an eggshell membrane-based biomaterial for GTR applications.

OBJECTIVES: Guided Tissue Regeneration (GTR) is a popular clinical procedure for periodontal tissue regeneration. However, its key component, the barrier membrane, is largely collagen-based and is still quite expensive, posing a financial burden to the patients as well as healthcare systems and negatively impacting the patient's decision-making. Thus, our aim is to prepare a novel biomimetic GTR membrane utilizing a natural biomaterial, soluble eggshell membrane protein (SEP), which is economical as it comes from an abundant industrial waste from food and poultry industries, unlike collagen. Additive polymer, poly (lactic-co-glycolic acid) (PLGA), and a bioceramic, nano-hydroxyapatite (HAp), were added to improve its mechanical and biological properties. METHODS: For this barrier membrane preparation, we initially screened the significant factors affecting its mechanical properties using Taguchi orthogonal array design and further optimized the significant factors using response surface methodology. Furthermore, this membrane was characterized using SEM, EDAX, and ATR-FTIR, and tested for proliferation activity of human periodontal ligament fibroblasts (HPLFs). RESULTS: Optimization using response surface methodology predicted that the maximal tensile strength of 3.1 MPa and modulus of 39.9 MPa could be obtained at membrane composition of 8.9 wt% PLGA, 7.2 wt% of SEP, and 2 wt% HAp. Optimized PLGA/SEP/HAp membrane specimens that were electrospun on a static collector showed higher proliferation activity of HPLFs compared to tissue culture polystyrene and a commercial collagen membrane. SIGNIFICANCE: From the results observed, we can conclude that SEP-based nanofibrous GTR membrane could be a promising, environment-friendly, and cost-effective alternative for commercial collagen-based GTR membrane products.

Sub-Diaphragmatic Haemangioma Suspected on F-18 Fdg Pet/Ct Confirmed by Rbc Scintigraphy.

A 53-year-old woman presented with left submandibular gland carcinoma. Contrast-enhanced computerized tomography done for staging revealed suspicious metastatic omental deposit adjacent to left hemi-diaphragm apart from primary and cervical nodal metastasis. Staging F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography showed high FDG uptake in the primary and metastatic left cervical lymph nodes. However, no FDG uptake was seen in left sub-diaphragmatic mass. Known vascular malformations sites in the left posterior triangle of the neck and liver hemangiomas also showed no uptake. This pattern of uptake raised a suspicion of multiple vascular malformations. Tc-99 m red blood cell scintigraphy was done which confirmed the nature of subdiaphragmatic lesion as haemangioma.

Rehabilitation of Atrophic Posterior Maxilla with Pterygoid Implants: A 3D Finite Element Analysis.

PURPOSE: Clinical cases have shown that pterygoid implants are a successful alternative solution for the rehabilitation of atrophic posterior maxillae; however, little research on the biomechanical behavior has been produced. This study created 3D models of pterygoid implant-supported prostheses and compared the stress and strain distributions in the pterygoid implants and surrounding bone using finite element analysis. MATERIALS AND METHODS: Three-dimensional models of a standardized human skull, pterygoid implants, and conventional dental implants were created using Simpleware, based on microcomputed tomography (micro-CT) and CBCT images. Six constructs with varying implant positions and numbers were designed to simulate various clinical scenarios for patients with complete maxillary edentulism. Finite element volume meshes were created and exported to ABAQUS, where the modulus of elasticity and Poisson ratio were assigned for each respective structure. Two load scenarios were simulated with conditions as follows: (1) 150-N axial loading; and (2) 150-N axial loading with simultaneous 50-N lateral loading. Then, the Von Mises stress and maximum principle strain distributions for all models were collected, analyzed, and compared. RESULTS: The maximum stress and strain in the pterygoid implants and surrounding bone under both loading scenarios were found in model 4, which had two pterygoid implants and two anterior implants, at the implant-abutment connection and crestal bone of the premolar region, respectively. The stress and strain in the pterygoid implants for all constructs analyzed were at values within the limit of material strength. Additionally, the stress and strain in the surrounding bone for all constructs analyzed were at values within the bone resorption threshold. The maximum stress in the surrounding bone for all models with pterygoid implants was lower than the stress in the control model, which contained no pterygoid implants. CONCLUSION: Pterygoid implants decreased the stress and strain level in the surrounding bone for all cases studied. Additional concern should be placed on the crestal bone of the premolar region and the implant-abutment connections of the pterygoid implants, since these locations had the highest recorded values.

Ameloblastoma: clinical presentation, multidisciplinary management and outcome.

We studied 21 patients who underwent radical ameloblastoma excision followed by immediate reconstruction. Comorbidities, consumption of alcohol and/or tobacco and BMI status did not contribute to an unfavorable outcome. Giant ameloblastoma (≥5 cm) and/or tumor involving bony curvatures increased surgical complexity, the incidence of complications and hospital stay.

Outcomes of Adult Ewing Sarcoma Treated with Multimodality Therapy: A Single-Institute Experience.

Introduction Ewing sarcoma (ES) is more common in children and relatively rare in adults. Adult ES has poor prognosis than children. Treatment approaches for adults have been extrapolated from pediatric experience. Data on adult ES are very few because of its rarity in adults. The present study was done to analyze the clinical profile and outcome of adult ES. Aims The aim was to study the clinical and pathological treatment and outcomes in adult ES. Subjects and Methods Between 2010 and 2017, a total of 73 ES patients with age more than 18 years were retrospectively analyzed. Survival analysis was done by plotting Kaplan-Meier curves. Results A total of 73 patients were diagnosed with ES during 2010 to 2017. Among them, 43 (58.9%) had localized disease with a median age of 24.5 years. Males were 44 (60.3%) and females were 29 (39.7). Pain (75.3%) was the most common symptom at presentation. Nine patients had incomplete details and were excluded from the analysis. Among 21 (28.8%) patients, the lung (61.9%) was the most common site of metastasis followed by the bone, bone marrow, and brain. The median number of chemotherapy cycles in the localized disease was 14 (range 1-17), and in metastatic disease, it was 4 (range 1-7). Univariate analysis was done with respect to age (< 25 vs. ≥25), gender, elevated or normal serum lactate dehydrogenase level, tumor size (< 8 cm versus ≥8 cm), site (axial versus extremity), and neoadjuvant chemotherapy (NACT) given or not. NACT had a significant impact on overall survival (OS) and the rest had no effect. At a median follow-up of 40 months, the 3-year OS in localized disease was 87.4%. In metastatic disease, the median OS was 13 months with 3-year OS of 26%. Conclusions Outcomes with multimodality therapy in adult ES patients with localized disease are comparable to that of a pediatric cohort. However, metastatic disease has poor survival.

A Modified Novel Technique for Condylar Positioning in Mandibular Bilateral Sagittal Split Osteotomy Using Computer-Assisted Designed and Computer-Assisted Manufactured Surgical Guides.

Current techniques for orthognathic surgery after Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO) rely on intermediate and final occlusal splints for proper positioning of the dental arches without any control in positioning the condyle and ramus segments. Setting the 2 condyles in centric relation in the glenoid fossae at fixation is paramount for condylar function and the accuracy and stability of postoperative occlusion. Usually the 2 ramus segments are manually positioned and fixated in the final position according to the surgeon's experience. This report describes a novel technique to position the condyle and ramus segments in centric relation using skeletal guides designed by computer-assisted designed and computer-assisted manufactured (CAD-CAM) technology. The skeletal guides have a double-U shape designed to be tooth borne on the distal segment and bone borne on the proximal segment. The guides fit on the last molar crown and the anterior border of the ramus; using these reference points will position the mandibular arch and 2 ramus segments in ideal centric occlusion and centric relation. The condyle position in the sagittal, horizontal, and transverse planes was analyzed by computed tomography and differences in measurements were calculated. This technique confirms precise control of the condylar segment in centric relation with stable centric occlusion using CAD-CAM guides during BSSO.

Influence of Alveolar Bone Defects on the Stress Distribution in Quad Zygomatic Implant-Supported Maxillary Prosthesis.

PURPOSE: The purpose of this study was to create three-dimensional composite models of quad zygomatic implant-supported maxillary prostheses with a variety of alveolar bone defects around implant sites, and to investigate the stress distribution in the surrounding bone using the finite element analysis (FEA) method. MATERIALS AND METHODS: Three-dimensional models of titanium zygomatic implants, maxillary prostheses, and human skulls were created and assembled using Mimics based on microcomputed tomography and cone beam computed tomography images. A variety of additional bone defects were created at the locations of four zygomatic implants to simulate multiple clinical scenarios. The volume meshes were created and exported into FEA software. Material properties were assigned respectively for all the structures, and von Mises stress data were collected and plotted in the postprocessing module. RESULTS: The maximum stress in the surrounding bone was located in the crestal bone around zygomatic implants. The maximum stress in the prostheses was located at the angled area of the implant-abutment connection. The model with anterior defects had a higher peak stress value than the model with posterior defects. All the models with additional bone defects had higher maximum stress values than the control model without additional bone loss. CONCLUSION: Additional alveolar bone loss has a negative influence on the stress concentration in the surrounding bone of quad zygomatic implant-supported prostheses. More care should be taken if these additional bone defects are at the sites of anterior zygomatic implants.

Feasibility of Axillary Reverse Mapping and Clinicopathological Features Predicting ARM Node Metastasis in Breast Cancer-a Pilot Study.

The axillary reverse mapping (ARM) technique has been described as an attempt to map and preserve the upper extremity lymphatic drainage during axillary lymph node dissection (ALND) and/or SLNB. This technique is based on the hypothesis that the lymphatic pathway from the upper extremity is not involved by metastasis from primary breast cancer. The ARM node/s however, has been found, in various studies, to be involved with metastatic foci in patients with extensive axillary lymph node metastases. Therefore, the oncological safety of this procedure has not yet been determined. In this pilot study, we assessed the ARM node intraoperatively for various parameters and compared it to final HPR, to try and determine the oncologic safety of preserving the ARM node. Seventy-two breast cancer patients were screened for this prospective pilot study which was planned to recruit 20 patients. The study was initiated on May 2014, 20 patients were recruited till July 2015. Eligibility criterion was as follows: patients requiring primary axillary lymph node dissection based on a clinically positive axilla. Forty-five patients were ineligible because they had either received neoadjuvant chemotherapy or underwent previous axillary surgery or axillary radiation (exclusion criteria). Seven patients refused to give consent. ARM node identification rate was 75%. The most common location of the ARM node was lateral to the latissimus dorsi pedicle (42.10%), none of them being malignant. None of the oval or firm nodes were malignant. Tumor deposits were identified in 13%. Fine-needle aspiration cytology (FNAC) had 100% specificity, 94.4% negative predictive value, 100% positive predictive value, and 50% sensitivity. ARM is feasible using blue dye alone, with an acceptable identification rate. Location, consistency, and intraoperative FNAC of the ARM node, put together, may be reliable parameters to predict involvement of the ARM node with metastasis.

Fibula Jaw in a Day: State of the Art in Maxillofacial Reconstruction.

Microvascular free tissue transfer has been one of the greatest milestones in reconstruction of the mandible and maxilla after tumor ablative surgery. Although fibula free flap reconstruction allows for immediate bony reconstruction, dental rehabilitation usually requires 6 to 12 months before it is completed. This can have a serious psychological impact on patients because they go without teeth during this timeframe. The "jaw-in-a-day" procedure was previously described by a group at New York University Medical Center. It allowed for tumor removal and full jaw reconstruction and dental rehabilitation in 1 surgery. This report describes 3 patients treated with this novel technique and adds to the 4 cases previously reported in the literature. To their knowledge, the authors are the second group to report on this technique. A series of photographs and videos are referenced in this article to illustrate the different steps used in this procedure.

Treatment outcomes with the use of maxillomandibular fixation screws in the management of mandible fractures.

PURPOSE: The purpose of this prospective randomized study was to assess whether uncomplicated mandible fractures could be treated successfully in an open or closed fashion using maxillomandibular fixation (MMF) screws. MATERIALS AND METHODS: This was a prospective institutional review board-approved study involving 20 adult patients who presented to the university emergency department or oral and maxillofacial surgical clinic with uncomplicated mandible fractures. Patients who met the exclusion criteria consented to enter the study in the open reduction internal fixation (ORIF) or the closed (MMF) study group. Six to 8 MMF screws were used to obtain intermaxillary fixation (IMF) in the 2 groups. Screw failure was documented. All screws were removed at 5 to 6 weeks postoperatively. Insertional torque (IT) was measured at time of screw placement to assess primary stability. Clinical and photographic documentation was performed to assess fracture healing, occlusion, and gingival health. Ten-centimeter visual analog scales were used to assess patient-centered outcomes. Cone-beam computed tomography was performed to assess the long-term effects on the periodontium and roots. A cost comparison was performed to determine whether the use of screws was cost effective compared with arch bars. RESULTS: Fifteen men and 5 women (mean age, 25.2 yr) entered the study. All patients displayed adequate fracture healing based on clinical examination. All patients had acceptable occlusion at 5 to 6 weeks postoperatively. Total screw failure was 27 of 106 screws (25.5%). Forty percent of screws placed in the MMF group failed compared with only 6% in the ORIF group. Gingival health scores were favorable. Factors that had a significant effect on screw failure included a lower IT (P = .002), use in closed (MMF) treatment (P < .001), and use in the posterior jaw (P = .012). Minimal pain was associated with the MMF screws and pre-existing occlusion was re-established based on patients' subjective responses. The MMF group reported a statistically significant lower quality of life (P < .001) compared with the ORIF group. There was only 1 screw site that had a facial cortical bone defect noted at 6-month follow-up CBCT examination. There were no discernible long-term root defects. Cost analysis showed that the use of MMF screws saved around $600 per patient in operating room usage cost alone compared with the estimated use of arch bars. CONCLUSIONS: Uncomplicated mandible fractures were successfully treated using MMF screws in open and closed treatments. However, the utility in closed treatment was decreased because of significant screw failure and patient noncompliance. The screws were well tolerated by the patients. There was minimal long-term damage to the periodontium and dental roots. The cost of screws was more than offset by time savings.

Biomechanical signals upregulate myogenic gene induction in the presence or absence of inflammation.

Inflammation of the muscle invariably leads to muscle cell damage and impaired regeneration. Biomechanical signals play a vital role in the regulation of myogenesis in healthy and inflamed muscle. We hypothesized that biomechanical signals counteract the actions of proinflammatory mediators and upregulate the basic helix-loop-helix and MADS box transcription enhancer factor 2 (MEF2) families of transcription factors, leading to increased myogenesis in inflamed muscle cells. For this purpose, C2C12 cells plated on collagenized silastic membranes were subjected to equibiaxial cyclic tensile strain (CTS) in the presence or absence of TNF-alpha, and the myogenic gene induction was examined over a period of 72 h. Exposure of cells to CTS resulted in a significant upregulation of mRNA expressions and synthesis of myogenic regulatory factors, MYOD1, myogenin (MYOG), MEF2A, and cyclin-dependent kinase inhibitor 1A (CDKN1A; p21) as well as muscle structural proteins like myosin heavy chain (MYHC) isoforms (MYH1, MYH2, and MYH4) and alpha-tropomyosin (TPM1), eventually leading to an increase in myotube formation. Contrarily, TNF-alpha suppressed the expression of all of the above differentiation-inducing factors in C2C12 cells. Further results revealed that simultaneous exposure of C2C12 cells to CTS and TNF-alpha abrogated the TNF-alpha-mediated downregulation of myogenic differentiation. In fact, the mRNA expression and protein synthesis of all myogenic factors (Myod1, Myog, Mef2a, Cdkn1a, Myh1, Myh2, Myh4, and Tpm1) were increased in stretched C2C12 cells despite the sustained presence of TNF-alpha. These results demonstrate that mechanotransduction regulates multiple signaling molecules involved in C2C12 cell differentiation. On one hand, these signals are potent transducers of myotube phenotype in myoblasts; on the other, these signals counteract catabolic actions of proinflammatory cytokines like TNF-alpha and allow the expression of myogenic genes to upregulate muscle cell differentiation.

Neurotransmitter phenotypes of intermediate zone reticular formation projections to the motor trigeminal and hypoglossal nuclei in the rat.

Numerous studies suggest an essential role for the intermediate (IRt) and parvocellular (PCRt) reticular formation (RF) in consummatory ingestive responses. Although the IRt and PCRt contain a large proportion of neurons with projections to the oromotor nuclei, these areas of the RF are heterogeneous with respect to neurotransmitter phenotypes. Glutamatergic, GABAergic, cholinergic, and nitrergic neurons are all found in the PCRt and IRt, but the projections of neurons with these phenotypes to the motor trigeminal (mV) and hypoglossal nucleus (mXII) has not been fully evaluated. In the present study, after small injections of Fluorogold (FG) into mV and mXII, sections were processed immunohistochemically to detect retrogradely labeled FG neurons in combination with the synthetic enzymes for nitric oxide (nitric oxide synthase) or acetylcholine (choline acetyltransferase) or in situ hybridization for the synthetic enzyme for GABA (GAD65/67) or the brainstem vesicular transporter for glutamate (VGLUT2). In three additional cases, FG injections were made into one motor nucleus and cholera toxin (subunit b) injected in the other to determine the presence of dual projection neurons. Premotor neurons to mXII (pre-mXII) were highly concentrated in the IRt. In contrast, there were nearly equal proportions of premotor-trigeminal neurons (pre-mV) in the IRt and PCRt. A high proportion of pre-oromotor neurons were positive for VGLUT2 (pre-mXII: 68%; pre-mV: 53%) but GABAergic projections were differentially distributed with a greater projection to mV (25%) compared to mXII (8%). Significant populations of cholinergic and nitrergic neurons overlapped pre-oromotor neurons, but there was sparse double-labeling (<10%). The IRt also contained a high proportion of neurons that projected to both mV and MXII. These different classes of premotor neurons in the IRt and PCRt provide a substrate for the rhythmic activation of lingual and masticatory muscles.